基于两步法研究盐离子预聚集对大豆分离蛋白凝胶性的影响  

Effect of Pre-Aggregation with Different Salt Ions on Gel Properties of Soy Protein Isolate Based on Two-Step Gelation Method

作　　者：王旭峰 于梦勤 王振忠[2] 罗凯云 刘树滔[1] WANG Xufeng;YU Mengqin;WANG Zhenzhong;LUO Kaiyun;LIU Shutao(College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China;China Rural Technology Development Center, Beijing 100045, China;College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China)

机构地区：[1]福州大学生物科学与工程学院,福建福州350108 [2]中国农村技术开发中心,北京100045 [3]湖南农业大学食品科学技术学院,湖南长沙410128

出　　处：《食品科学技术学报》2022年第1期65-75,共11页Journal of Food Science and Technology

基　　金：国家自然科学基金资助项目(32101986);福建省自然科学基金资助项目(2020J05128)。

摘　　要：为了改善大豆分离蛋白(soy protein isolate,SPI)凝胶品质,提出了一种两步制备凝胶的新方法:首先利用3种不同浓度(0~15 mmol/L)的硫酸盐(CaSO_(4)、MgSO_(4)和ZnSO_(4))对SPI进行预聚集处理,然后通过添加CaSO_(4)至盐离子总浓度为35 mmol/L使蛋白质凝胶化,并探讨了不同盐离子预聚集对SPI结构及凝胶特性的影响。结果表明:盐离子与蛋白质分子之间的相互作用是自发的吸热反应,由熵变驱动,滴定ZnSO_(4)引起的热量变化较CaSO_(4)和MgSO_(4)更为剧烈;盐离子的加入引起了SPIα-螺旋结构含量上升,β-折叠结构含量下降及荧光强度降低。在同一浓度条件下,经ZnSO_(4)诱导的SPI聚集体颗粒的粒径、表观黏度均显著大于其他两种盐离子(P<0.05),说明Zn^(2+)的聚集能力更强。流变性分析结果表明,相较于未经预聚集处理的SPI凝胶,经10.0 mmol/L CaSO_(4)、10.0 mmol/L MgSO_(4)、5.0 mmol/L ZnSO_(4)预聚集处理的SPI凝胶的弹性分别提高了49.5%、30.0%和59.9%,但蛋白质分子过度预聚集会导致凝胶强度的下降。利用不同盐离子对SPI进行适当预聚集处理能够有效提高蛋白质凝胶性能,研究结果旨在为SPI凝胶制品质构性质的改良提供一种绿色、简洁的新思路。In order to improve the gel quality of soy protein isolate(SPI),a new two-step gel-preparation process was applied in this study.First,SPI dispersions were pre-aggregated by using three sulfates(CaSO_(4),MgSO_(4),and ZnSO_(4))at different concentrations(0~15 mmol/L)and then gelled by adding CaSO_(4)up to a total salt concentration of 35 mmol/L.The pre-aggregation effects of different salt ions on the structure and gelation of SPI were investigated.The results showed that the interaction between salt ions and protein molecules was a spontaneous endothermic reaction driven by entropy change,and the heat change caused by titration of ZnSO_(4)was more intense than that of CaSO_(4)and MgSO_(4).The addition of salt ions caused the increase in the content ofα-helix,but decrease ofβ-sheet structure and fluorescence intensity.At the same addition level,the particle size and apparent viscosity of SPI aggregates induced by ZnSO_(4)were significantly larger than those induced by the other two salt ions(P<0.05),indicating that Zn^(2+)had stronger aggregation ability.The rheological results showed that compared with SPI gel without pre-aggregation,the elastic modulus of the SPI gel prepared by pre-aggregation with 10.0 mmol/L CaSO_(4),10.0 mmol/L MgSO_(4)and 5.0 mmol/L ZnSO_(4)were increased by 49.5%,30.0%and 59.9%,respectively.However,excessive aggregation of protein molecules led to the decrease in gel strength.Therefore,proper pre-aggregation of proteins with different salt ions could effectively improve the gel properties.These results might provide a green and simple method for the texture improvement of SPI gel products.

关 键 词：大豆分离蛋白 盐离子 相互作用 预聚集 凝胶性 

分 类 号：TS201.7[轻工技术与工程—食品科学] TS210.1[轻工技术与工程—食品科学与工程]